916462017-09-16Triton Hopper: Exploring Neptune's Captured Kuiper Belt ObjectActiveJul 2015Jun 2016We propose a hopper vehicle using a radioisotope thermal rocket engine, using in-situ propellant, to explore Neptune's moon Triton. This moon is thought to be a captured Kuiper Belt object due to its retrograde orbit and surface. It has a very thin atmosphere. Because of the variety of terrain and a gravity of only 8% that of Earth, a rocket- powered vehicle, or "hopper," is a desirable choice for exploration, capable of hemispheric traverses and atmospheric sampling during hops. To be capable of a robust program of exploration, the vehicle must be capable of refueling using available resources. Power will come from an isotope heat source, which will also be used to power the rocket. Trades of using ice collected on or below the surface versus collecting the very thin atmosphere using cryogenic pumping will be made to downselect the propellant for the isotope powered rocket. The COMPASS team will be used to develop the concept which will demonstrate both radioisotope thermal propulsion and in-situ refueling.The Triton Hopper addresses NASA’s strategic goals 2, 3, and 6 by exploring the Triton environment, the first exploration of a KBO which could hold clues to how the solar system formed. It will create new technologies in the form of a semi-autonomous planetary hopping vehicles which use frozen gases for propellants and would capture the imaginations of educators and students by sharing with them exploration of a completely new environment on a foreign world. Triton Hopper will also address the NASA technology areas of Space Power and Energy Storage, Robotics and Autonomous Systems, Communications and Navigation Systems, Science Instruments and Sensors, Nanotechnology, Materials, and Thermal Management Systems. The Triton Hopper study will be the first real definition of a ‘frozen gas rock’ powered hopper, since prior ISRU fuel concepts were fed with atmospheric gas. The Triton Hopper would be a pathfinder in combining ISRU acquisition and science, since the sampling system doubles as the propellant production system. Addressing the challenge of autonomous hopper exploration in an extremely cold outer solar system environment, Triton Hopper serves as a pathfinder for other exploration of the frozen surfaces of icy moons such as Enceladus and Europa, as well as more distant objects such as Sedna, Charon, Centaurs, and Trans-Neptunian and Kuiper-belt objects.22332522In-Space Propulsion TechnologiesNASA Innovative Advanced ConceptsSpace Technology Mission DirectorateGlenn Research CenterGRCNASA CenterClevelandOHOhioTherese GriebelSteven OlesonGeoffrey Landishttps://www.nasa.gov/directorates/spacetech/home/index.html